Railway hotbox safety device



April 1966 c. R. STRANDT ETAL 3,248,539

RAILWAY HOTBOX SAFETY DEVICE Filed Aug. 31, 1964 INVENTORJ. E Jfrandf Char/6.; 14/ Jf/zwdf United States Patent 3,248,539 RAILWAY HUTBOX SAFETY DEVICE Charles R. Strandt, 3227 N. 58th St., and Charles W. Strandt, 6217 Yeelrer, both of Kansas City, Karts. Filed Aug. 31, 1964, Ser. No. 393,820 4 Claims. (Cl. 246-169) This invention relates to new and useful improvements in railway safety apparatus, and has particular reference to a device for detecting hotboxes, i.e., overheated wheel bearings, Whenever they occur and for automatically taking remedial action. 'Undetected hotboxes, with result-ant damage to or even complete destruction of wheel hearings or journals, are a major cause of derailments, as well as necessitating expensive repairs and replacement of parts. Reliance is usually made on the visual detection of smoke and/or flame to indicate the occurrence of hotboxes, but this method is often unreliable since the inspecting workman must often view the wheels from considerable distances and from disadvantageous angles, and since the wind sometimes blows the smoke toward the side of the train opposite to that from which the workman is conducting his inspection.

Accordingly, the principal object of the present invention is the provision of a safety device operable to detect a hotbox whenever it occurs, and further to apply the train brakes automatically to bring the train to a halt, in order that the hotbox may be located and the proper remedial steps may be taken before proceeding. Generally, this object is accomplished by providing an air conduit interconnected at one end to the train air line and vented at its opposite end to the atmosphere, said conduit extending closely adjacent the journal of one wheel. All of the wheels of each car are so equipped. Directly adjacent the journal, the conduit is releaseably sealed by a fusible plug which is adapted to be heated and melted whenever the journal temperature exceeds a predetermined maximum safe level, thereby venting the train air line and applying the train air brakes. Customarily, each car is equipped with an equalizing air cylinder having a double-acting piston therein operable to apply the brakes when moved in one direction and having spring means for moving the piston in the opposite direction to release the brakes whenever air pressure at both sides of the piston is equalized. The'train air line runs the length of the train, being supplied with air from acompressor at the engine. At each car, the train line is interconnected directly to end of the equalizing cylinder for releasing the brakes, and is connected to the opposite end of the cylinder through a check valve and an air reservoir tank. Thus whenever the train line pressure is reduced, either intentionally as in normal braking or accidentally as by the severing of the train line, or by the fusing of a plug of our safety device, the check valve closes and the brakes are applied by air from the reservoir tank.

Another object is the provision of a safety device of the character described wherein the fusible plug may constitute a member of a valve sealing the conduit and normally held closed by the'pressure of the train line, whereby the conduit will remain sealed even if the plug itself should become loosened by vibration or the like.

A further object is the provision of a safety device of the character described including heat gathering and conducting means for transmitting heat from the journal to the fusible plug, whereby the plug is heated as closely as possible to the actual journal temperature.

A still further object is the provision of a safety device of the character described wherein the fusible plug,

' or the plug and immediately adjacent portions of the 'ice removed and replaced rapidly and conveniently even while the train is located remotely from repair shops, in order to permit immediate return of the car to normal service.

Other objects are simplicity and economy of construction, efiiciency and dependability of operation, and adaptability for use with wheel journals of various styles and types.

With these objects in view, as well as other objects which will appear in the course. of the specification, reference will be had to the accompanying drawing, wherein:

FIG. 1 is a fragmentary vertical sectional view through a journal box of a railway car, showing a portion of the wheel truck, and taken at right angles to the journal axis on line I-I of FIG. 2,

FIG. 2 is a fragmentary sectional view taken on line II-II of FIG. 1, with parts left in elevation and parts broken away,

FIG. 3 is an enlarged fragmentary sectional view taken on line IIIIII of FIG. 2, and

FIG. 4 is a fragmentary sectional view taken on line IV-1V of FIG. 3.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to the wheel trucks of a rail-way car, it being understood that 1 each car is normally equipped with two trucks and that conduit, constitute a separable cartridge which may be said trucks support the weight of the car. Each truck normally has four journal boxes formed integrally therewith, one journal box being shown at 4, said journal boxes being horizontally aligned in pairs, transversely of the car, so that each pair carries a car axle 6. A car wheel 8 is pressed on each axle adjacent each journal box 4, and said axle extends outwardly from said wheel into said journal box, through a hole 10 provided therefore in inner end wall 12 of said box. The portion of the axle within the journal box forms a cylindrical hearing journal 14, the upper portion of which is rotatably engaged in a bearing block 16 which in turn is carried by a supporting block 18 seated against the top Wall 28 of the journal box. The lower portion of the journal box is filled with oil-impregnated waste material 22, journal 14 wiping against said waste material to be coated with oil thereby. The outer end of the journal box is provided with a hinged access door 24 to permit servicing of parts within the box. Hotboxes normally occur due to failure of lubrication, as for example by exhaustion of the oil from the waste, or by compaction of the waste material so that it no longer engages the journal.

The safety device forming the subject matter of the present invention includes a cartridge indicated generally by the numeral 26 and including a short pipe 28 disposed vertically within the journal box, adjacent journal portion 14 of the axle. Disposed in the central portion of said pipe, substantially at the level of the journal axis, is a plug 38 formed of an alloy capable of being melted at the maximum safe temperature to which journal 14 may be heated by friction without causing damage to the journal or to bearing block 16. A melting point of perhaps 200-300 degrees Fahr. is believed to be satisfactory, although this may be altered as desired as may be indicated by experiment. The function of the plug is to seal pipe 28 against the passage of air therethrough. It may be poured into the pipe and allowed to solidify therein, or it may be preformed to a diameter slightly les than the bore of the pipe, and simply dropped therein. In the latter case, the plug is supported at the upper end of a tube 32 inserted slidably into pipe 28, said tube being aflixed in said pipe so as to prevent leakage of air therebetween, as for example by having the lower end of the tube formed with a peripheral flange 34 which is clamped between the lower end of pipe 28 and a union coupling 36 afiixed to said pipe. Tube 32 and plug 30 thus act as a valve, tube 32 forming the valve seat and plug 30 forming a valve disc, sealing pipe 28 against the passage of air therethrough. As will appear, plug 30 is held against tube 32 by the operating air brake pressure, normally about 80 p.s.i., and is sufiiciently soft to be indented by the tube to provide an efiicient seal.

Afiixed around pipe 28, so as to enclose completely that portion of the pipe containing plug 30, is a metallic block 38 to which is affixed a cylindrically curved plate 40, the axis of curvature of said plate coinciding with the axis of journal 14, and said plate being slightly spaced apart from the surface of said journal. Plate 40, block 38 and pipe 28 are preferably formed of a good heatconducting material such-as copper, and have the function of gathering heat from journal 14 and conducting it to plug 30, in order that said plug will be maintained as closely as possible to the temperature of the journal despite possible random air currents in the journal box, which might otherwise cause a large and highly variable temperature differential.

Union coupling 36 connects the lower end of pipe 28 detachably to the upper end of a vertical discharge pipe 42, said discharge pipe extending downwardly through a hole provided therefor in a lower wall of the journal box, and is secured therein by a pair of lock nuts 44 threaded thereon at opposite sides of said box wall. Tapered washers 46 may be used under said lock nuts to accommodate said lock nuts if, as shown, the pipe is not disposed normally to the journal box wall. The discharge pipe is open to the atmosphere at its lower end, and should bestraight, coaxial with pipe 28, and of at least as large internal diameter as pipe 28.

The upper end of pipe 28 is detachably interconnected, as by a union coupling 48, to a tubular L-fitting 50, said L-fitting extending through a vertical Wall of the journal box and being secured therein by lock-nut 52. Thus discharge pipe 9 and L-fitting 50 provide rigid support for cartridge pipe 28, and hold it fixedly in the desired position. Externally of the journal box, the discharge end of a manually operable stopcock 54 is interconnected to L-fitting 50. The inlet end of said stopcock has a flexible hose 56 interconnected therewith. It will be understood that the opposite end of said hose is interconnected directly into the train line of the air brake system as described above, and that it is flexible in order to accommodate the normal relative movement between the body of the car and the wheel truck 2.

In operation, stopcock S4 is normally open as shown, but the conduit venting the train air line to the atmosphere, and consisting of hose 56, stopcock 54, L-fitting t cartridge pipe 23 and discharge pipe 42, is sealed by plug 39, so that no air escapes, and the brake system of the train is not affected. However, should a hotbox began to develop, as represented by a rise in the temperature of journal 14 to or above a predetermined maximum safe level, plug 30 will of course melt and be blown by air pressure through and out from discharge pipe 42. The train air line is thus immediately vented to the atmosphere, causing a reduction in the line pressure, which then causes the train brakes to be applied to bring the train to a halt, as previously described. The apparatus whereby the pressure reduction applies the brakes has heretofore been generally described, and and is so common and well known as not to require specific illustration or detailed description.

If plug 30 is originally poured into pipe 28 in molten form, it will be tightly bonded with the pipe walls, and valve seat tube 32 may therefore sometimes be dispensed with. However, it has been found that without tube 32 the plug may be loosened in pipe 28 by extended periods of vibration encountered in normal operation of the train, and therefore be dislodged and blown free to cause stoppage of the train even though the journal is not in fact overheated. The valve seat provided by tube 32 preadjacent access door 24.

vents this possibility. Another advantage of the use of tube 32 is that after the plug has melted, the entire cartridge 26 need not be removed and replaced, but can be reconditioned for use simply by disconnecting the couplings 36 and 48 and dropping a new plug 30 therein. However, whether the entire cartridge or only plug 30 need be replaced, the operation may be performed easily, rapidly and conveniently within a very few minutes.

Discharge pipe 42 is preferably straight, aligned coaxially wit-h cartridge pipe 28, and of at least as large internal diameter as said cartridge pipe, in order that if only the surface portions of plug 30 should be melted, and therefore the core portion thereof should move into said discharge pipe while still solid, said core portion will not lodge or become jammed in the discharge pipe, but will be blown free. If it should lodge in the discharge pipe, it might again seal the pipe, thereby maintaining air pressure and allowing the train to continue in operation with an undetected hotbox.

Stopcock 54 may be closed after a stoppage, either to permit replacement of cartridge 26 or plug 30 to allow resumption of normal operation, after first of course correcting the cause of the overheating as by adding oil to waste material 22, or to seal the train line to permit buildup of pressure therein to release the brakes in the event it is decided to pull the car with the hotbox at a slow speed to the nearest siding for repair.

The safety device is readily adaptable to many different environments. For example, in journal boxes not having sufficient space at the sides of journal 14 to accommodate cartridge 26, said cartridge could be extending across the free end of the journal, immediately In cars equipped with roller bearings, a portion of cartridge 26, such as block 38, could be detachably connected directly to the housing of the outer roller race, which is generally exposed and accessible. In essence the invention requires only a conduit extending adjacent the journal, with plug 30 0 its equivalent disposed therein.

While we have shown and described a specific embodiment of our invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What we claim as new and desire to protect by Letters Patent is:

1. In combination with a railway car air brake system including a compressed air supply line and means operable by reduction of pressure in said supply line to apply the brakes of said car, and in which each of the car wheels is supported by a journal enclosed in a journal box and subject to overheating if not properly lubricated, a safety device comprising:

(a) a plurality of conduits each interconnected at one end into said supply line, extending through one of said journal boxes, and having its opposite end open to the atmosphere externally of said journal box, said conduit including a length of pipe disposed immediately adjacent the journal within said journal box, and

(b) a plug of fusible material disposed in and normally sealing said pipe against the passage of air therethrough, said plug being meltable at a temperature corresponding to the maximum safe operating temperature of said wheel journal.

2. A safety device as recited in claim 1 with the addition of:

(a) a heat conducting block afiixed to said pipe and enclosing the portion thereof in which said plug is normally disposed, and

(b) a heat conducting plate affixed to said block and overlying a substantial area of said wheel journal in closely spaced apart relation thereto.

3. A safety device as recited in claim 1 wherein said conduit includes a discharge portion disposed down- 5 6 stream of said pipe containing said plug, said discharge stream with respect to the direction of air flow, and portion being straight, coaxial with said pipe, and of at (c) a fusible plug carried loosely in said pipe and least as large crosssectional area as said pipe. normally urged against said valve seat by air pres- 4. In combination with a railway car air brake syssure to seal said pipe, said plug being meltable at tern including a compressed air supply line and means 5 a temperature corresponding to the maximum safe operable by reduction of pressure in said supply line to operating temperature of said wheel journal. apply the brakes of said car, and in which each of the car wheels is supported by a journal subject to overheat- References Cited y the Examine! ing if not properly lubricated, asafety device compris- UNITED STATES PATENTS ing:

(a) a plurality of conduits each interconnected at 10 2089369 10/1937 Heckert 246169 one end into said supply line extending adjacent 2501715 3/1950 Ferguson 246169 2,973,429 2/1961 Clark et al. 246169 one of said wheel journals, and having its opposite end open to the atmosphere, said conduit includ- BENJAMIN HERSH Primary Examiner. ing a length of pipe disposed immediately adjacent 5 said journal, EUGENE G. BOTZ, Examiner. (b) a valve seat fixed in said pipe and facing up- 

1. IN COMBINATION WITH A RAILWAY CAR AIR BRAKE SYSTEM INCLUDING A COMPRESSED AIR SUPPLY LINE AND MEANS OPERABLE BY REDUCTION OF PRESSURE IN SAID SUPPLY LINE TO APPLY THE BRAKES OF SAID CAR, AND IN WHICH EACH OF THE CAR WHEELS IS SUPPORTED BY A JOURNAL ENCLOSED IN A JOURNAL BOX AND SUBJECT TO OVERHEATING IF NOT PROPERLY LUBRICATED, A SAFETY DEVICE COMPRISING: (A) A PLURALITY OF CONDUITS EACH INTERCONNECTED AT ONE END INTO SAID SUPPLY LINE, EXTENDING THROUGH ONE OF SAID JOURNAL BOXES, AND HAVING ITS OPPOSITE END OPEN TO THE ATMOSPHERE EXTERNALLY OF SAID JOURNAL BOX, SAID CONDUIT INCLUDING A LENGTH OF PIPE DISPOSED IMMEDIATELY ADJACENT THE JOURNAL WITHIN SAID JOURNAL BOX, AND (B) A PLUG OF FUSIBLE MATERIAL DISPOSED IN AND NORMALLY SEALING SAID PIPE AGAINST THE PASSAGE OF AIR THERETHROUGH, SAID PLUG BEING MELTABLE AT A TEMPERATURE CORRESPONDING TO THE MAXIMUM SAFE OPERATING TEMPERATURE OF SAID WHEEL JOURNAL. 